From 62cc67b9df273be18fcb09a071592dedf751c90a Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 21 Feb 2011 16:49:58 +1100 Subject: powerpc/pmac/smp: Properly NAP offlined CPU on G5 The current code soft-disables, and then goes to NAP mode which turns interrupts on. That means that if an interrupt occurs, we will hit the masked interrupt code path which isn't what we want, as it will return with EE off, which will either get us out of NAP mode, or fail to enter it (according to spec). Instead, let's just rely on the fact that it is safe to take decrementer interrupts on an offline CPU and leave interrupts enabled. We can also get rid of the special case in asm for power4_cpu_offline_powersave() and just use power4_idle(). Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/head_64.S | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/powerpc/kernel/head_64.S') diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 782f23df7c85..271140b38b6f 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -536,6 +536,13 @@ _GLOBAL(pmac_secondary_start) add r13,r13,r4 /* for this processor. */ mtspr SPRN_SPRG_PACA,r13 /* Save vaddr of paca in an SPRG*/ + /* Mark interrupts soft and hard disabled (they might be enabled + * in the PACA when doing hotplug) + */ + li r0,0 + stb r0,PACASOFTIRQEN(r13) + stb r0,PACAHARDIRQEN(r13) + /* Create a temp kernel stack for use before relocation is on. */ ld r1,PACAEMERGSP(r13) subi r1,r1,STACK_FRAME_OVERHEAD -- cgit v1.2.2